384 SCIENCE PROGRESS. 



of electricity have their attraction very much diminished 

 when they are immersed in a medium of high specific in- 

 ductive capacity like water. It follows from this that when, 

 during the changes and chances of their molecular life, two 

 ions come in very close contact with particles of solvent, 

 their mutual attraction may be less than the attraction be- 

 tween one or both of them and the surrounding medium, 

 and dissociation may take place. This force attracting a 

 charged ion to the solvent, which is of the same nature as 

 that between a charged body and a non-electrified conductor 

 near it, will prevent its combining with an opposite ion until 

 one happens to get so close that the other forces are over- 

 come. This will of course occur less frequently as the 

 number of ions gets less, and so in very dilute solutions the 

 dissociation remains almost complete. It is not necessary 

 to assume that the ion remains always in combination with 

 the same molecules of water, which would involve a trans- 

 ference of solvent under the action of the electric forces. 

 In the jostling crowd of solvent molecules it is soon passed 

 on to others, and so works its way towards its destined 

 pole. As long as it meets few distractions, in the shape of 

 ions of opposite kind, on the road, its speed depends only 

 on itself, the solvent and the electric forces, but when such 

 encounters become frequent it sometimes forms connections 

 which, while they last, render the ion inactive, and totally 

 prevent the performance of its proper electrolytic work. 

 This loose combination with the solvent would give the 

 ions freedom to travel, without allowing them to wander 

 about under what some consider the insufficient chaperonage 

 of their own electric charges. 



The fact that water, which has a high specific inductive 

 capacity, makes such a good electrolytic solvent is of great 

 interest. The power which a liquid has of enabling sub- 

 stances dissolved in it to carry electricity may be largely 

 due to the reduction which it causes in the electric forces 

 holding their molecules together, and the consequent in- 

 creased facility for the production and preservation of dis- 

 sociated ions. This property would depend on the specific 

 inductive capacity, and it therefore becomes most interesting 



